The present invention relates to a pressurized filling apparatus for filling a container with a filling liquid such as a carbonated drink, and more specifically, to a filling apparatus for filling a container with a filling liquid such as a non-carbonated drink that can also be used for unpressurized filling and a filling method therefor.
A well-known pressurized filling apparatus that fills a container with a filling liquid such as a carbonated drink accommodates a filling liquid in a storage tank together with a pressurized carbonated gas, supplies the carbonated gas in the storage tank to the interior of a sealed container via a gas passage formed in a filling valve and pressurizes the interior of the container, opens the filling valve to start a filling operation when the pressure in the container becomes equal to that in the storage tank, ends the filling operation once the filled amount reaches a predetermined value, and stops applying pressure to the interior of the container and then unseal the container. Further, Japanese Patent Laid-Open No. 11-342994 discloses an unpressurized filling method of using such a pressurized filling apparatus to allow the storage tank to communicate with the atmosphere to fill the container with a non-carbonated drink.
If the above described pressurized filling apparatus is used for an unpressurized filling operation, the following problems may occur: First, in the unpressurized filling operation, a filling liquid may be heated and sterilized, so that it may be filled into a container while hot. With the pressurized filling apparatus, since the container is sealed, the filling operation must be performed while exhausting air from the container via the gas passage formed in the filling valve. However, hot steam from the hot filling apparatus may flow into the gas passage and may be cooled and condensed there, so that the diameter of the passage may be reduced to make the exhaust inefficient, thereby increasing the time required for the filling operation. Further, in a pressurized filling operation, the interior of the container is pressurized to slightly expand the container, so that the level of the liquid after the filling operation is slightly lower than that prior to the pressurization. On the other hand, in the unpressurized filling operation, the interior of the container is not pressurized, so that if the same amount of fluid as that in the pressurized filling operation is filled into the container, then the filling liquid may reach the tip of the gas passage inserted into the container and enter the gas passage. Accordingly, the entered filling liquid must be removed before the next container is filled with the filling liquid.
To solve these problems, the above mentioned Japanese Patent Laid-Open No. 11-342994 provides an auxiliary gas chamber such that in the unpressurized filling operation, a low pressure gas from the auxiliary gas chamber is fed into the gas passage before the operation to drop a bubble-like liquid remaining in the gas passage, into the container. This solves all the above-described problems. However, the auxiliary gas chamber is used only for the unpressurized filling operation and is unnecessary for the pressurized filling operation. Further, no problem occurs if the filling liquid does not enter the gas passage, but if it does due to the large amount of the fluid, then a certain amount of the filling liquid to be filled into the container during the current filling operation is dropped during the next operation, causing an inaccurate amount of filling liquid to be filled into the container.
Thus, a first aspect of the present invention is a filling apparatus comprising a storage tank having a gas space in an upper part thereof to store filling liquid therein, a filling valve having a liquid passage to which the filling liquid is supplied and a valve element that opens and closes the liquid passage to fill a container with the filling liquid, a gas passage formed in the filling valve, a connection passage that connects the gas space in the storage tank to the gas passage, a gas valve provided in the connection passage to open and close the connection passage, seal means for sealing the container while the liquid passage and the gas passage are in communication with the container, an exhaust passage that allows an interior of the sealed container to communicate with an exterior thereof, an exhaust valve that opens and closes the exhaust passage, and filled amount detecting means for detecting the amount of filling liquid filled into the container, the apparatus sealing the container, then opening the liquid passage to start a filling operation, and closing the liquid passage to end the filling operation once a signal from the filled amount detecting means indicates that the amount of filling liquid filled into the container has reached a predetermined value,
wherein the apparatus is provided with a pressure gas passage through which pressure gas is supplied to the sealed container, a pressure gas valve that opens and closes the pressure gas passage, and a pressure gas source that supplies pressure gas to the pressure gas passage so that both the connection passage and the pressure gas passage are open after the container has been sealed and before the fluid channel is closed.
Further, a second aspect of the present invention is a filling method for a filling apparatus comprising a storage tank having a pressure gas space in an upper part thereof to store filling liquid therein, a filling valve having a liquid passage and a gas passage to fill a container with the filling liquid, seal means for sealing the container, and filled amount detecting means for detecting the amount of filling liquid filled into the container, the apparatus filling the sealed container with a predetermined amount of filling liquid, the method comprising:
providing a pressure gas passage through which pressure gas is supplied to the sealed container, and a pressure gas source that supplies pressure gas to the pressure gas passage,
sealing the container using the seal means, then supplying gas in the storage tank to the container via the gas passage in the filling valve, supplying the pressure gas from the pressure gas passage to the container, thereby making a pressure in the container equal to that of the gas in the storage tank, subsequently opening the filling valve to start a filling operation, continuing the filling operation while exhausting gas from the container via the gas passage, and closing the filling valve to end the filling operation once a signal from the filled amount detecting means indicates that the amount of filling liquid filled into the container has reached a predetermined value.
Furthermore, a third aspect of the present invention is a filling method for a filling apparatus comprising a storage tank having a gas space in an upper part thereof to store a filling liquid therein, a filling valve having a liquid passage and a gas passage to fill a container with the filling liquid, a connection passage connected to the gas passage, seal means for sealing the container, an exhaust passage that allows an interior of the sealed container to communicate with an exterior thereof, and filled amount detecting means for detecting the amount of filling liquid filled into the container, the apparatus filling the sealed container with a predetermined amount of filling liquid, the method comprising:
providing a pressure gas passage through which a V pressure gas is supplied to the sealed container, and a pressure gas source that supplies pressure gas to the pressure gas passage,
sealing the container using the seal means, then supplying the pressure fluid from the pressure gas passage to the container, allowing the pressure gas to flow through the gas passage and connection passage via the container to discharge droplets adhering to inner surfaces of the gas and connection passages, subsequently opening the filling valve to start a filling operation, continuing the filling operation while exhausting gas from the container via the gas passage, and closing the filling valve to end the filling operation once a signal from the filled amount detecting means indicates that the amount of filling liquid filled into the container has reached a predetermined value.
According to the construction of the first aspect of the present invention, for a pressurized filling operation, both the gas passage connected to the storage tank and the pressure gas passage connected to the pressure gas source are opened so that gases supplied through both passages can be used to pressurize the interior of the container. Consequently, compared to the prior art in which only the gas supplied through the gas passage connected to the storage tank is used for pressurization, the time required to pressurize the interior of the container can be reduced, and a possible decrease in the concentration of the gas in the storage tank can be restrained.
Further, in an unpressurized filling operation, gas from the pressure gas passage connected to the pressure gas source is supplied to the interior of the container and then flows through the gas passage. Accordingly, droplets condensed in the gas passage can be removed without the use of the construction of an auxiliary gas chamber, which is unnecessary for pressurized filling.
Furthermore, according to the filling method of the second aspect of the present invention, both the gas passage connected to the storage tank and the pressure gas passage connected to the pressure gas source are opened so that gases supplied through both passages can be used to pressurize the interior of the container. Consequently, compared to the prior art in which only the gas supplied through the gas passage connected to the storage tank is used for pressurization, the time required to pressurize the interior of the container can be reduced, and a possible decrease in the concentration of the gas in the storage tank can be restrained.
Moreover, according to the filling method of the third aspect of the present invention, in an unpressurized filling operation, gas from the pressure gas passage connected to the pressure gas source is supplied to the interior of the container and then flows through the gas passage. Accordingly, droplets condensed in the gas passage can be removed without the use of the construction of an auxiliary gas chamber, which is unnecessary for pressurized filling.
Above and other objects, features and advantages of the present invention will become apparent from the following detailed description of an embodiment thereof with reference to the attached drawings.